This invention relates to deferred action type batteries, and, in particular, to a multi-cell, vacuum activated battery.
Wet cell batteries generally tend to deteriorate once the electrolyte or other activator fluid is present within the cells. Such batteries are best preserved over extensive periods prior to use, by maintaining the cells in a sealed condition without activator fluid, which is added only shortly prior to use.
For certain military uses such as artillery shells and the like, the operation of some components is powered by primary batteries. Since operation is desired only at the moment of use, the batteries are of the deferred action type, and it is essential that the battery be activated substantially instantaneously when it is called upon for service.
Reserve type batteries are known which are activated by crushing a frangible vial containing a fluid electrolyte so that the electrolyte can come into contact with the plate elements and thus be activated and ready for service. Such batteries have been found useful in electric fuzes for rotating ordinances where the shock of setback upon firing is used to crush the vial and where the centrifugal force due to the spinning of the projectile makes possible the rapid and uniform filling of the battery cells. In the prior art, a setback force is used to fracture a sealed frangible vial containing electrolyte. Centrifugal force produced by the spinning of the projectile forces the electrolyte into the cells of the battery. Both forces are needed in this type of battery.
In U.S. Pat. No. 4,218,525 entitled "Reserve Type Battery", a spin force is not used to activate the battery, but rather, a plunger is used. The battery is activated by a gas generator moving the plunger by gas pressure or by a spring mechanism. The spring and the gas generator are actuated by setback force. The plunger crushes the frangible vial and then acts as the centrifugal force did in other batteries, forcing the released electrolyte into the battery cells.
The problem with the mentioned batteries is that a specific force is necessary for the activation of the battery. In a great many batteries, setback force and centrifugal force are both required, and in others setback force alone or a detonator is used.
In U.S. Pat. No. 4,699,854 issued to Applicant on Oct. 13, 1987 entitled "Multi-Option Deferred Action Battery", a deferred action battery having multiple methods of activation was disclosed. While this battery has multiple methods of activation, it is limited to one battery cell due to the location and structure of the cell and the speed with which the bibulous material takes up the electrolyte.